pymysql()
  MySQL database connection.
  
  Requires: pymysql python module
  
  Usage: db.pymysql(host='127.0.0.1',port=3306,dbname='sagator',
                    dbuser='sagator',dbpasswd='xxxxxx')
  
  Parameters:
        host            - database server hostname or unix socket path
        port            - tcp socket port for database server
        dbname          - database name
        dbuser          - authorization username
        dbpasswd        - authorization password
  
  Database creation script:     scripts/db/mysql.sh